Retention for Holder Shank

ABSTRACT

In one aspect of the present invention, a degradation assembly has a holder comprising a first end and a second end and a shank with a longitudinal central bore having an opening at an end proximate the second end. The shank portion of the holder has an inside diameter of the bore and an outside diameter wherein either the inner diameter or the outer diameter comprise at least one recess disposed therein which comprises a depth of less than the distance between the inner diameter and the outer diameters.

BACKGROUND OF THE INVENTION

Formation degradation, such as asphalt milling, mining, or excavating, may result in wear on attack tools. Consequently, many efforts have been made to efficiently remove and replace these tools.

U.S. Pat. No. 6,585,326 to Sollami, which is herein incorporated by reference for all that it contains, discloses a bit holder with its mating bit block utilizing a slight taper in the bit block bore, and a tapered shank on the bit holder that includes a second larger diameter tapered distal segment that combines with an axially oriented slot through the side wall of the bit holder shank to allow a substantially larger interference fit between the distal tapered shank segment and the bit block bore than previously known. When inserting the bit holder in the bit block bore, the distal first tapered segment resiliently collapses to allow insertion of that segment into the bit block bore. A second shank tapered portion axially inwardly of the first distal tapered portion. The dual tapered shank allows the insertion of the bit holder in the bit block with an interference fit that provides a secure mounting of the bit holder in the bit block.

U.S. Pat. No. 3,865,437 to Crosby, which is herein incorporated by reference for all that it contains, discloses a mining tool of the type in which a pick style bit is rotatably mounted in a bore in a support member and is retained therein by retaining means integrally formed on the bit. The retaining means advantageously takes the form of at least one radial projection on the rear end of the bit shank with the bit shank being slotted to impart radial resilience thereto so the bit can be assembled with the support member and readily disassembled therefrom while being retained therein during work operations. The support member may comprise a support block adapted for being fixed to a driver with a sleeve rotatable in a bore in the block and, in turn, rotatably receiving the bit. The sleeve may be slotted axially from the rear end so as to have lateral resilience and be formed with one or more radial projections or protrusions at the rear end so that the sleeve, also, is releasably retained in the block by retaining means integral therewith.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the present invention, a degradation assembly has a holder comprising a first end and a second end and a shank with a longitudinal central bore having an opening at an end proximate the second end. The shank portion of the holder has an inside diameter of the bore and an outside diameter having at least one recess disposed therein.

The at least one recess may extend along at least a portion of the shank of the holder. The at least one recess may comprise various geometries: hemispherical, rectangular, triangular, round, or combinations thereof. The inside and outside diameters may comprise a plurality of recesses. In some embodiments, the plurality of recesses disposed in the inside and outside diameters may be offset from each other. A distance between the recesses may comprise a length of 5% to 50% the circumference of their respective diameters. The recesses of the inner diameter may have a distance between recesses less than a distance between recesses of the outer diameter. The at least one recess may have a depth of 5% to 50% the distance from the inner diameter to the outer diameter and may comprise a width of 50% to 20% the circumference of its respective diameter. In some embodiments, the inner or outer diameter of the shank may comprise a taper.

In another aspect of the present invention, a degradation assembly has a holder fitted within a block attached to a driving mechanism, the holder having a longitudinal central bore having an opening at an end opposite the driving mechanism. A high impact resistant tool has a carbide bolster axially intermediate a steel shank and an impact tip. The shank portion of the holder has an inside diameter of the bore and an outside diameter having at least one recess disposed therein.

The shank of the holder may be press-fit into a bore of the block. The press-fit may have a 0.01 to 0.10 inch interference fit between the shank of the holder and the bore of the block. The impact tip may comprise a superhard material bonded to a cemented metal carbide substrate at a non-planar interface. The superhard material may comprise a substantially pointed geometry with an apex comprising a 0.050 to 0.200 inch radius, and a 0.100 to 0.500 inch thickness from an apex to the non-planar interface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional diagram of an embodiment of a plurality of tools on a rotating drum attached to a motor vehicle.

FIG. 2 is a perspective diagram of an embodiment of a tool holder.

FIG. 3 is an exploded diagram of an embodiment of a degradation assembly.

FIG. 4 is a cross-sectional diagram of an embodiment of a shank of a tool holder.

FIG. 5 is a cross-sectional diagram of another embodiment of a shank of a tool holder.

FIG. 6 is a cross-sectional diagram of another embodiment of a shank of a tool holder.

FIG. 7 is a cross-sectional diagram of another embodiment of a shank of a tool holder.

FIG. 8 is a cross-sectional diagram of another embodiment of a shank of a tool holder.

FIG. 9 is a cross-sectional diagram of another embodiment of a shank of a tool holder.

FIG. 10 is a perspective diagram of another embodiment of a tool holder.

FIG. 11 is a perspective diagram of another embodiment of a tool holder.

FIG. 12 is a perspective diagram of another embodiment of a tool holder.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 is a cross-sectional diagram of an embodiment of a plurality of tools 101 attached to a rotating drum 103 connected to the underside of a pavement recycling machine 100. The recycling machine 100 may be a cold planer used to degrade man-made formations 104 such as pavement. Tools 101 may be inserted into a sleeve, the sleeve being fit within a holder 102. The holder 102 may be fit within a block that is attached to the rotating drum 103. The holder 102 may hold the tool 101, at an angle offset from the direction of rotation, such that the tool 101 engages the pavement at a preferential angle. In some embodiments, the tools may be adapted to rotate within the holder.

Referring now to FIG. 2, the holder 102 has a first end 200 and a second end 201 and a shank 202 with a longitudinal central bore 203. The shank portion 202 of the holder 102 may be press-fit into a block of a driving mechanism. The central bore 203 has an opening proximate the second end 201. The shank portion 202 of the holder 102 has an inner diameter 204 of the bore 203 and an outer diameter 205. The inner and outer diameters 204, 205, have at least one recess 206 disposed therein. In the preferred embodiment, the inner diameter 204 and the outer diameter 205 have a plurality of recesses 206. The plurality of recesses 206 may extend along at least a portion 207 of the shank 202. In this embodiment, the recesses 206 extend along the entire length of the shank 202. In the preferred embodiment, the recess 206 may comprise a hemispherical geometry 208. In the preferred embodiment, the depth of the recess is less than 90 percent of the thickness of between the inner and outer diameters. In some embodiments the recess is between 75 and 25 percent.

The recesses may add compliancy to the shank of the holder, allowing the holder to be press fit into the block easier than a holder of substantially the same material and diameters but without the recesses. The recesses may be disposed generally axially along the shank. In some embodiments, the recesses may be disposed spirally or angularly with respect to the central axis of the bore. The recesses may be slots or corrugations with a depth less than the thickness between the inner and outer diameters. The recesses may extend axially along the entire length of the shank or less. In some embodiments, the recesses extend less than 75 percent of the length of the length of the shank. The recesses of the inner diameter and the recesses of the outer diameter may be offset from each other such that there is a distance between the recesses of equal to or greater than the depths of the recesses.

In some embodiments of the present invention, the recesses are machined or forged into the shank. In other embodiments, the shank is cast and the recesses are formed during a casting process. The casting process may incorporate molds and/or dies.

FIG. 3 discloses an exploded diagram of an embodiment of a high impact resistant tool 101, a holder 102, and a block 301. The holder 102 may be fitted within the block 301 attached to a driving mechanism. The holder 102 has a longitudinal central bore 350 at a first end 200 opposite the driving mechanism; the central bore 350 being adapted to receive a steel shank 303 of the tool 101. The tool 101 has a carbide bolster 302 axially intermediate the steel shank 303 and an impact tip 304. The impact tip 304 may comprise a superhard material 307 bonded to a cemented metal carbide substrate 308 at a non-planar interface 309. The superhard material 307 may comprise polycrystalline diamond, vapor-deposited diamond, natural diamond, cubic boron nitride, infiltrated diamond, layered diamond, diamond impregnated carbide, diamond impregnated matrix, silicon bonded diamond, or combinations thereof. The superhard material 307 may comprise a substantially pointed geometry with an apex 310 comprising a 0.050 to 0.200 inch radius 311, and a 0.100 to 0.500 inch thickness 312 from the apex 308 to the non-planar interface 309.

The shank portion 202 of the holder 102 has a longitudinal central bore 203 having an opening proximate the second end 201 of the shank 202. The outer diameter 205 of the shank 202 may have a plurality of recesses 206 disposed therein. In this embodiment, the shank 202 of the holder 102 may be tapered and may be press-fit into a bore 305 of the block 301. The shank 202 may have diameter greater than a diameter of the bore 305 disposed in the block 301. The press-fit may comprise an interference fit 306 of 0.01 to 0.10 inch between the shank 202 of the holder 102 and the bore 305 of the block 301. The plurality of recesses 206 disposed within the shank 202 may help in the removal and replacement of the holder 102. The plurality of recesses 206 formed in the shank 202 may allow for a reliable interference fit 306 such that the holder is held tightly within the block during operation. The recesses 206 may also allow for easy and quick removal of the holder from a block.

FIGS. 4 through 9 illustrate various geometries of at least one recess 206 disposed within the inner and outer diameters 204, 205, of the shank 202 of the holder. FIG. 4 illustrates a shank 202 having a plurality of recesses 206 comprising a hemispherical geometry 208. In this embodiment, the plurality of recesses 206 of the inner and outer diameters 204, 205, is alternating such that a recess of the outer diameter is offset with the recesses on the inner diameter. The plurality of recesses 206 may comprise a depth 401 of 5 to 50% the distance 402 from the inner diameter to the outer diameter. The recesses may also have a width 403 of 5 to 20% the circumference of the respective diameters. A distance 405 between the recesses may have a length of 10 to 50% the circumference of the respective diameters. In this embodiment, the plurality of recesses of the inner diameter 204 comprises a distance between recesses less than a distance between recesses of the outer diameter 205.

FIG. 5 illustrates a shank 202 having a plurality of recesses 206 with a rounded geometry 500. The shank may be press-fit into a bore disposed within a block. The press-fit may be between the bore of the block and outer edges 501 of the outer diameter 205 of the shank 202. Referring now to FIG. 6, the plurality of recesses 206 formed in the inner diameter 204 of the shank 202 may comprise a triangular geometry 600 while the plurality of recesses 206 formed in the outer diameter 205 may comprise a rounded geometry 500. In this embodiment, the plurality of recesses 206 of the inner and outer diameters aligns. FIG. 7 discloses a shank having a plurality of recesses 206 formed in the outer diameter 205 of the shank 202. In this embodiment, the recesses formed in the outer diameter 205 may comprise a depth 401 greater than 50% of the distance 402 between the inner and outer diameters 204, 205. The plurality of recesses 206 may also comprise a rectangular geometry 700.

FIG. 8 shows an embodiment of a shank 202 having at least one recess 206 within the inner diameter 204 and at least one recess 206 disposed within the outer diameter 205. FIG. 9 illustrates an embodiment of a shank 202 having at least one recess 206 disposed within the outer diameter 205.

FIG. 10 discloses a perspective view of an embodiment of a holder 102 comprising a set of threads 1000 about the inner diameter 204 of the shank 202. In this embodiment, the central bore 203 of the holder 102 may be adapted to receive an attachment mechanism. The attachment mechanism may be a spacer which is adapted to radially expand a portion of the shank 202 proximate the plurality of recesses 206.

FIG. 11 discloses an annular recess 1206 substantially normal to a central axis of the holder. FIG. 12 discloses a recess 2206 which forms a spiral along the length of the holder.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention. 

1. A degradation assembly, comprising: a holder comprising a first end and a second end and a shank with a longitudinal central bore having an opening proximate the second end; the shank portion of the holder comprising an inner diameter of the bore and an outer diameter; wherein both the inner diameter and the outer diameter comprise at least one substantially axial recess disposed therein which comprises a depth of less than the distance between the inner diameter and the outer diameters.
 2. The assembly of claim 1, wherein the recesses extends along a length of the shank of the holder.
 3. The assembly of claim 1, wherein the recesses comprises a hemispherical geometry.
 4. The assembly of claim 1, wherein the recesses comprises a rectangular geometry.
 5. The assembly of claim 1, wherein the recesses comprises a triangular geometry.
 6. The assembly of claim 1, wherein the recesses comprises a round geometry.
 7. The assembly of claim 1, wherein the inside and/or outside diameters comprise a plurality of recesses.
 8. The assembly of claim 7, wherein the plurality of recesses of the inside and outside diameters are offset from each other.
 9. The assembly of claim 7, wherein a distance between the recesses comprises is 5 to 50% the circumference of their respective diameters.
 10. The assembly of claim 7, wherein the recesses of the inner diameter are spaced closer together than the recesses of the outer diameter.
 11. The assembly of claim 1, wherein the at least one recess comprises a depth of 5 to 50% the distance between the inner diameter to the outer diameter.
 12. The assembly of claim 1, wherein the at least one recess comprises a width of 5 to 20% of the circumference of either the inner or outer diameter.
 13. The assembly of claim 1, wherein the outer diameter of the shank comprises at least one taper.
 14. The assembly of claim 1, wherein the recesses are formed in casting process.
 15. A degradation assembly, comprising: a holder fitted within a block attached to a driving mechanism, the holder comprising a longitudinal central bore having an opening at an end opposite the driving mechanism; a high impact resistant tool comprising a carbide bolster axially intermediate a steel shank portion and an impact tip; and the shank portion of the holder comprising an inside diameter of the bore and an outside diameter: wherein both the inner diameter and the outer diameter comprise at least one substantially axial recess disposed therein which comprises a depth of less than the distance between the inner diameter and the outer diameters.
 16. The assembly of claim 15, wherein the shank of the holder is press-fit into a bore of the block.
 17. The assembly of claim 16, wherein the press-fit comprises a 0.01 to 0.10 inch interference fit between the shank of the holder and the bore of the block.
 18. The assembly of claim 15, wherein the impact tip comprises a superhard material bonded to a cemented metal carbide substrate at a non-planar interface.
 19. The assembly of claim 18, wherein the superhard material comprises a substantially pointed geometry with an apex comprising a 0.050 to 0.200 inch radius, and a 0.100 to 0.500 inch thickness from an apex to the non-planar interface.
 20. The assembly of claim 15, wherein an attachment mechanism is fitted within an opening of the central bore at an end proximate the driving mechanism. 